I much prefer Annabel to Susanna, personally, but I find Rosalie and Susanna to be a slightly better match. As for a nn for Susanna, I like Annie and Sosie best, personally, although I think Posy would be downright adorable, if you could squeeze it out.

I prefer Susanna. Too many -bel names around, in my opinion (which is too bad, I love the classic Belle!). Also, I like the feel of Susanna and Rosalie together better. They're both feminine yet spunky, and classics.